Protective surfaces for drug-coated medical devices

Abstract

Medical balloons having one or more folds, on which are disposed protective surfaces e.g., protective lines or strips, and at least one therapeutic agent between the lines. The protective surfaces prevent, inhibit, or reduce the contact between therapeutic agent on one area, e.g., a surface area, and an opposing area or therapeutic agent on the opposing area when the balloon is folded. The protective surfaces also prevent, inhibit, or reduce loss of therapeutic agent from the balloon surface as a result of, for example, contact with a medical device during expansion or removal of a protective sheath. Also a medical device delivery system comprising a medical device surrounded by a retractable sheath, wherein protective surfaces are disposed on the sheath.

We claim: 
     
       1. A medical balloon comprising at least one fold that brings a first area of the balloon into opposition with a second area of the balloon, wherein:
 disposed on the first area is a first set of protective surfaces and between said protective surfaces are one or more layers of a first therapeutic agent; 
 disposed on the second area is a second set of protective surfaces and between said protective surfaces are one or more layers of a second therapeutic agent, which may be the same as or different from the first therapeutic agent, and 
 wherein the protective surfaces are placed in positions such that, when the balloon is folded, at least one protective surface of the first set of protective surfaces is brought into contact with at least one protective surface of the second set of protective surfaces, and further wherein the layer of first therapeutic agent has a height not exceeding the height of any protective surface adjacent to it, and the layer of second therapeutic agent has a height not exceeding the height of any protective surface adjacent to it. 
 
     
     
       2. The medical balloon of  claim 1 , wherein the protective surfaces of the first set are of about the same height as each other and the protective surfaces of the second set are of about the same height as each other. 
     
     
       3. The medical balloon of  claim 2 , wherein some or all of the protective surfaces are protective lines. 
     
     
       4. The medical balloon of  claim 2 , wherein the first protective surfaces and the second protective surfaces each comprise at least two parallel protective lines, and further wherein, when the balloon is folded such that the first area is brought into opposition with the second area, the parallel protective lines of the first protective surface are not parallel with the parallel protective lines of the second protective surface. 
     
     
       5. The medical balloon of  claim 4 , wherein the parallel protective lines of the first protective surface intersect with the parallel protective lines of the second protective surface at an angle of between about 20° and about 90°. 
     
     
       6. The medical balloon of  claim 5 , wherein the angle is about 90°. 
     
     
       7. The medical balloon of  claim 6 , wherein the therapeutic agents are independently selected from paclitaxel, sirolimus (rapamycin), tacrolimus, everolimus, biolimus, and zotarolimus, or a combination thereof. 
     
     
       8. The medical balloon of  claim 5 , wherein the first protective surfaces and the second protective surfaces comprise a polyether block amide material. 
     
     
       9. The medical balloon of  claim 5 , wherein the balloon comprises a polyether block amide. 
     
     
       10. The medical balloon of  claim 5 , wherein the balloon is non-compliant. 
     
     
       11. The medical balloon of  claim 10 , wherein the protective surfaces have a shore D hardness of about 67 D to about 70 D. 
     
     
       12. A medical device comprising:
 a catheter, and 
 the medical balloon of  claim 4 . 
 
     
     
       13. The medical device of  claim 12 , further comprising a retractable sheath. 
     
     
       14. A method of treating restenosis comprising delivering a therapeutic agent to a target site, wherein the therapeutic agent is transported to the target site by the medical balloon of  claim 4 .